Stoker



0a. 23, 1945. BEIQNETT 2,387,383

STOKER Original Filed Sept. 3, 1936 l N V EN TOR. Joseph 5. Benne H This application is a division of my Patented Oct. 23, 1945 v v STOKER e Josephs. Bennett, Merion, Pa., assignor, by mesne assignments to American Engineering Company, Philadelphia, Pa., a corporation of Pennsylvania Original application September s, 1936, Serial No.

Divided and this application Novembet 5, 19 11erial No. 417,919

co-pending application, Serial No 99,234, filed September 3, 1936, and the invention herein involved relates to stokers; and more particularlyto extensiongrates or overfeed sections of stokers of the inclined grate, multiple retort, underfeed type.

1 One object of the present invention is to pro section, particularlyadapted for use with fluid cooled stokersof the underfeed type, the grate sectionbeing so dispiasedas to effectively feed'fuel and residuetoan ashpocket as well as to break up any clinkers forming at the top of the fuel bed.

Other and further objects will become apparent as the description of the invention progresses.

Of the drawing:

Fig. 1 is a side elevational view partly in section of the lower portion of a stoker showing the structure of the improved overfeed section thereof.

Fig. 2 is a plan view of the structure shown in Fig. 1.

Fig- 3 is a detail view of the mechanism for adjusting the lower ends of the grate bars shown in Fig. 1.

Fig. 4 is a side view of one of the extension rate bars.

Fig. 5 is an end view looking from left to right n of the grate bar shown in Fig. 4, and

Fig. 6 1s an end view looking from right to left of the grate bar shown in Fig. 4.

Referring to the drawing, the numeral I indicates generally a stoker of the inclined grate type having an upper underfeed section 2 and a lower over-feed section 3. The underfeed section consists of alternately disposed retorts 4 and tuyere rows 5. Fuel entering the stoker is fed along the underfeed section" thereof in a well-known manner to the overfeed section 3 which in turn feeds it to an ash pocket l9 provided at the end of the stoker.

Each tuyre row, only one of which is shown herein, has mounted thereon a fluid conducting tube l5, These tubes extend beyond the lower ends of the tuyre rows and form a portion of the overfeed section 3. The tubes l5, as shown A further. object is to provide a novel grate zfolai s. (01.122-376) more particularly in Fig. 1, are bent downwardly as shown at I! to form a portion of the ash pocket l9 and terminate in a header 20. Header 28 is connected to a boiler, not shown, by any suitable downtake connections in a well-known manner. The upper ends of tubes l5 are also connected to the boiler. Mounted in intimate contact with each dead plate 12, only one of which is shown, is a pair of tubes 23. These tubes extendupwardly from header 28 in parallel relation with the extensions of tubes lfiand terminate in a header, not shown, mounted beneath the stoker and connected to the boiler by any suitable uptake connections.

Mounted for oscillatory movement between the tubes l5 and 23 are a series of grate bars l4.

Each grate bar 14 comprisesan'elongated body portion hi having an upper serrated fuel supporting and feeding portion 14 The rearwardly disposed end of each grate bar 14 terminates in a downwardly extending portion 14 which forms a portion of the upper wall of the'ash pocket l9. Depending fromtheupper, forwardly disposed end of each grate bar 14 isan arcuate portion 14 having a relatively large circular opening 8| provided therein for receivingan operatin cam as will appear more fully hereinafter.

As shown more particularly in Figs. 1 and 4, the lower edge 15 of each grate bar It rests upon a rollerlfi rotatably mounted at the free end of an arm ll secured to a shaft l8. Shaft 18 extends through the side wall it! of the furnace and is journalled in a bearing provided in a bracket 90 secured to the said wall. The outer end of shaft 18 has secured thereto a gear 8| which meshes with a second gear 82 mounted on a shaft 83 supported in a second bearing 85 of bracket 90. A hand crank 88 is secured to one end of shaft 83. Also secured to shaft '18 is a ratchet wheel 8'! which is held against movement in one direction by a pawl 88, pivotally supported on bracket 98. Thus upon rotation of gears 82 and. 8| by crank'fli, arms 11 will be swung about their pivot to raise or lower supporting rollers 16 to adjust the lower end of grate bars. "i4, By engagement of the pawl 88 with ratchet wheel 81 the parts are retained in adjusted position.

A shown in Fig. 1 a cam 92 is mounted in the circular opening 9| of each grate bar 14. The cams 92 are eccentrically mounted on a shaft 92' operated by an electric motor 93 through a chain and sprocket mechanism 94 and reduction gearing indicated generally at 95. Thus upon operation of motor 93, earns 92 are actuated in an orbital path, thereby imparting a reciprgcatory as 1 well as a rocking movement to the grate bars 1-4. In the event it is desired to increase the effectiveness of the overfeed section, the lower ends of grate bars 14 are elevated, as shown in broken line inF 'e'.v 1, to bring the upperserrated edges thereofla greater distance above the tubes l5 and 23. i

In order to prevent the passage of siftings past the upper ends of the grate bars 14, a series of plates 96 are provided between the dead plate l2 and the said grate bar '|;4., The plates ,96 are disposed between the tubes and 23, as shown in Fig. 2, and are pivoted-near their forwardly disposed ends as shown at 9|. The lower rearwardly disposed ends 98 of plates 96 engage scribed also is of such a character that it may form'the entire grate of the stoker, if it is so desired.

While the embodiment herein shown and described is admirably adapted to fulfill the objects primarily stated, it is' to be understoodthat the invention is not to be limited thereto, since it may be embodied in other forms, all coming within the scope of the claims which follow.

What is claimed is: 1. An inclined overfeed section for stoker furnaces, comprising a series of laterally spaced fluid the upper edges of the grate bars 74 and thus 7 form a seal between the points of contact thereof. These plates are held in contact with the grate bars 14 by any suitable means, such as by weights 99.

, The fluid conducting tubes l5 protect the tuyres 5 andextension grate bars 14 against the intense heat of the furnace. The tubes 23 also protect the grate bars 14, the sealing plates 96, and the dead plate l2 against the heat of the furnace. The tubes l- 5 and 23 also act as a slag screen chilling'any molten slag forming in the fuel bed before it comes in contact with the tuyres, sealing plates, and grate bars. The tubes l5 and 23 also form a portion of the extension grate proper and constitute the front wall of the ash pocket l 9. v

From the foregoing description it is seen that a hi hly efficient overfeed section has been provided which effectively feeds the consumed or partially consumed fuel towardthe ash pocket of the stoker and at the same time breaks up any clinkers forming at the top of the fuel bed By employing fluid cooled structures, it is also I conducting members, individual grate bars disposed between said members and lying in juxtaposition therewith, a support comprising an antifriction roller for the lower end of each of said grate bars, a rocker arm for rotatably supporting each of said rollers, a shaft secured to said rocker arm, gearing for actuating said shaft to adjust the position of said rollers, means for holding said shaft in adjusted position, cam meansfor imparting vertical and longitudinal movements to each of said grate bars, and ower meansfor actuating said cams. j

2. An inclined overfeed section for stoker furnaces, comprising a series .of laterally spaced fluid conducting members, individual grate bars disposed between said members and lyinginjuxtaposition therewith, a support comprising an anti-friction roller "for the lower end of each of said grate bars, arocker armfor rotatably supporting each of said rollers, a shaft secured to said rocker arm, gearing for actuating said shaft to adjust the position of said rollers, means for holding said shaft in adjusted position, cam means for imparting vertical and longitudinal movements to eachof said grate bars, power means for actuating said cams, means forming a seal at the upper ends of each of said grate bars, and means for holding said sealing means in, contact with said grate bars.

JOSEPH s; BENNETT; 

